Allowable Stress for Pipe Spec API 5L Gr. X42 - 1966
Allowable Stress for Pipe Spec API 5L Gr. X42 - 1966
(OP)
Does anyone know the allowable stress, S, for Pipe Spec API 5L Gr. X42 per ANSI B31.3-1966. I am probably going to have to rerate an old pipeline after inspection in accordance with its original allowable stress. Thank you in advance.





RE: Allowable Stress for Pipe Spec API 5L Gr. X42 - 1966
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Allowable Stress for Pipe Spec API 5L Gr. X42 - 1966
You said B31.3
I gave you the allowable stress for B31.4 or 8 pipeline codes. I think the allowable stress for X42 under B31.3 was/is 20 ksi, but wait for confirmation.
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Allowable Stress for Pipe Spec API 5L Gr. X42 - 1966
RE: Allowable Stress for Pipe Spec API 5L Gr. X42 - 1966
1.) Why was a PIPELINE built to B31.3?
2.) Its very unusual to use X grade material in B31.3 construction, since as decastro mentioned, there is no credit for the extra strength, so X GRADE its a waste of good money.
Those resons make me think that the pipeline was not built to B31.3, but B31.4 if liquid, or B31.8 if gas. I recommend you do some in depth "digging" and confirm the code under which it was constructed was indeed B31.3. I think it might not have been 31.3.
Lastly, if you want to rerate, why not recode as well? If it is a pipeline, rerate it under the proper code. If it is a regulated pipeline in the U.S., the design and construction must conform to CFR Title 49 Part 192 or 194 (based on B31.4/8), so if rerated and/or operated under B31.3, you may face some nonconformities. Hay, its worth a phone call or two.
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Allowable Stress for Pipe Spec API 5L Gr. X42 - 1966
Cpinner, let us know how it turns out.
RE: Allowable Stress for Pipe Spec API 5L Gr. X42 - 1966
If it has class 300 fittings and holds a strength test, would it not be rated to 740 psi?
Greg Lamberson, BS, MBA
Consultant - Upstream Energy
Website: www.oil-gas-consulting.com
RE: Allowable Stress for Pipe Spec API 5L Gr. X42 - 1966
You are so right. No DOT, DOE... even Medicare, right? Big brother wasn't so big back then.
OK, that aside, today there would be no need to rerate using B31.3 if this pipe is indeed a "pipeline". If its a regulated DOT pipeline, it would even be inappropriate, as B31.3 does not address many factors of pipeline design...Area Class Factors for example.
CPinner,
Have a look at the Scope paragraphs of the codes and determine if your "pipeline" falls under the definition of "Pipeline" or some other facility.
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Allowable Stress for Pipe Spec API 5L Gr. X42 - 1966
The design allowable stress per B31.3 is 20 ksi. In terms of rerating, 49 CFR may well apply if pipeline is in the USA, in which case you must use the requirements therein.
RE: Allowable Stress for Pipe Spec API 5L Gr. X42 - 1966
RE: Allowable Stress for Pipe Spec API 5L Gr. X42 - 1966
The Houston, TX Main Library is an excellent resourse for old Codes and ASTMs. I have obtained specs from the 1940s there and the librarians have been very helpful.
RE: Allowable Stress for Pipe Spec API 5L Gr. X42 - 1966
For example a 6" sch40 could be anywhere from 1205 to 2130 MAOP (from my quickie tables).